2006 Honda Insight MT Build Thread

[mpg_numbers_guy]

Due my 12V being practically worthless, I've hooked the IMA back up. IMA light is off and it's charging while at idle (haven't gone for a drive yet since I hooked it back up).

Summed up, my IMA symptoms were/are:

• IMA light & CEL
• No assist or regen indicated on dash display
• No autostop
• Car still starts off hybrid battery
• Car still assists during acceleration (can feel it, but nothing displayed)
• If regen is happening I can't tell due to nothing being displayed
• IMA battery pack at 163V (now 169V after grid charging for an hour)

Will check the ground straps when I take the car into my dad's dealership to get the valves adjusted and general inspection performed. Not sure if they've been replaced or not. Carfax doesn't indicate they are but I haven't gone through all of the maintenance records yet.

If I end up getting rid of the battery due to it being a truly degraded battery rather than ground straps, I'll do a full bypass. By the time the lithium replacement becomes available I'll get a dead pack for the computers like suggested.

If charging at idle is affected, and charging above 4000 RPM doesn't happen (not that I'd rev that high anyway), what's the point of disconnecting the BCM? I thought just switching the pack off let it charge between 1500 and 4000 RPMs but disconnecting the BCM let it charge perfectly at any RPM.

If I get rid of the battery and cut the rear springs, I might just lower the whole car by half an inch, or an inch, for better handling and fuel economy.

Since disconnecting the 12V from the car to disable the battery reset the car's computers, no IMA charge is indicated on the battery despite there being a charge in it yet until it recalibrates. Reconnected the battery, grid charged it from 163V to 169V, and we'll see what happens on the drive into the dealership tomorrow.

If I end up keeping the hybrid battery installed, should I still replace the dying 12V battery? A lithium alternative looks like a fun project if it isn't too complicated, but I don't want to spend the $$$ unless it's necessary.

Originally Posted by Vman455

I just had an idea (which I think I'll try on my car too):

Find one of the narrow coolant hoses running across the engine bay, if any (in the Prius, there's one that runs across the front of the car, from one of the overflow tanks to the radiator). Slit an oversized duct lengthwise, wrap around the coolant line, tape up. Easy air warmer. It will work best on trips long enough to get the coolant up to operating temperature, and won't be as effective as a dedicated intercooler because of the insulative properties of the rubber, but also not as complicated or expensive. And you could still route the end of the intake duct to the catalytic converter if you want.

Be sure to post pictures when you do it! I might follow suit. Still have to reconfigure my air intake to make it an actual warm air intake.

[Ecky]

A dying 12v battery can also wreak all sorts of havoc on how the car runs. Definitely definitely replace it. One morning I came out and found my car would start via the IMA system but the dashboard was completely dark and the car would not exceed 19mph, and ran really rough. I was terrified something truly bad had happened, but replacing the 12v battery fixed it.

Based on what you've said, I think there's a strong chance the issues you're seeing with the IMA are 12v related, either the ground straps, battery or both. Get those replaced ASAP or it might get worse and you'll end up stranded somewhere. All existing hybrids all l still need a functional and healthy 12v system.

The reason to unplug the BCM with a bypass is that with a really bad IMA, you won't get 12v charging at all and the car can actually die while you're driving it. By disconnecting the BCM the car will run and drive fine (assuming your 12v battery is ok too) you'll just get a temporary loss of 12v charging at high RPM and your headlights will dim a bit at low RPM. Reason being, the voltage coming from the IMA motor varies greatly based on RPM, anywhere from asking 70v at idle to 300v+ at redline. The DC-DC converter can run with an input as low as 70v but not at full output, and when the battery is installed it's always fed around 165v. At high RPM the DC-DC temporarily disconnects because it's input voltage is too high.

[mpg_numbers_guy]

Just arrived at the dealership. After resetting and grid charging the battery the battery worked absolutely flawlessly. Never went down more than 2 bars after full assist acceleration. Lowest the battery got was 3 bars below full. The trip finished with the battery at 1 bar below full. Got 71.2 MPG over 28 miles, and that's with my front brakes rubbing terribly, which I will be fixing asap. Probably costing me at least 10 MPG - wheels spin only 1 1/2 times when I spin them. Highly doubt a dying hybrid battery would've performed like that, even after a grid charge, but I obviously don't know that much about the IMA system yet.

- 75-85 MPG cruising between 43 and 56 MPH (constant throttle, including hills).
- 105-120 MPG cruising between 29 and 35 MPH (mostly flat, sheltered between trees and buildings.
- If it's flat and sheltered, 30-40 mph speeds work best, if hilly and/or exposed to wind, etc., 45-50 mph seems to work best for fuel economy.

Trip fuel economy passed 60 MPG at about the 9.5 mile mark. Removed my "warm" air intake since intake temp is still stuck at 60 F for some reason.

Going to have the ground straps inspected today. The guy who will be working on the Insight has graciously allowed me to be there to see how he does everything. Should be a good learning experience.

How complicated and expensive was your supercapaciter/lithium battery setup? If it's fairly complicated, is there a simpler way to do a lithium battery without spending $700 for one off of Amazon?

[Ecky]

Originally Posted by mpg_numbers_guy

Going to have the ground straps inspected today. The guy who will be working on the Insight has graciously allowed me to be there to see how he does everything. Should be a good learning experience.

The ground straps are simple copper wires that connect the engine (and IMA motor) to the frame of the car. The engine sist on rubber mounts and is not grounded (without these straps) to the frame of the car. If the copper wires get corroded, all sorts of awful electrical problems ensue. You can have IMA system problems, the engine can misfire, you might find that the DC-DC converter shuts off or your cluster does weird things.

Originally Posted by mpg_numbers_guy

How complicated and expensive was your supercapaciter/lithium battery setup? If it's fairly complicated, is there a simpler way to do a lithium battery without spending $700 for one off of Amazon?

The supercapacitors would be mostly unnecessary if you don't plan to start the car with them, and only ever start using the hybrid pack. Be aware that the Insight will not start from the hybrid pack if temperature outside drops below 0F as this can be dangerous for NiMH cells. However this is doubly true of lithium, so if the car will ever sees subzero temps, you realistically should not use a lithium battery. EVs which have lithium batteries will run a resistive heater to keep the batteries above freezing, but if left in the cold too long without charging the batteries run dead from trying to stay warm.

Normal lead acid batteries are pretty durable and would not be destroyed if attempting to use them below freezing (dangerous for lithium) or subzero (dangerous for NiMH).

LiFePO4 is the "safe" lithium chemistry, which won't catch on fire. Lithium Ion is the unsafe one which is lighter, has higher capacity, and can suddenly burst into flames if you're not very careful with them.

The supercapacitors in my car are to handle the starting and transient loads of running the car. The lithium (LiFePO4) battery is just a backup, in case I leave my lights on or want to run the radio for a while with the car off.

You can make your own inexpensive lithium pack with 4 of these:

https://www.ev-power.eu/LiFePO4-smal...e-CE.html#tab2

^ This *may* start the car fine in good weather but low temperatures or repeatedly using the 12v starter would be hard on a lithium battery this small.

BatterySpace sells already-assembled packs similar to using 4 of the above cells, for a small premium - $133 for the battery, or $189 for the same battery but with a balancing circuit and some other safeguards inside.

https://www.batteryspace.com/lifepo4...assed-dgr.aspx

I probably wouldn't pair just supercapacitors with the IMA system, as when the car goes into auto-stop it needs a fairly long lasting 12v battery to keep all of the electronics running.

[mpg_numbers_guy]

So just inspected my ground wires. The 12V to chassis is fine - looks practically new. HOWEVER, the one that goes from the chassis to transmission looks completely corroded, and the one that goes from the chassis to intake or IMA motor (whatever that black box is, I haven't opened it yet to find out) is corroded AND CUT. Literally cut in half and not connected at all.

The mechanic that did my valve adjustment graciously hooked up his diagnostic computer to the Insight for me to use to diagnose the problem.

(Shoutout to Chris from Crown Motors in Holland, MI! Amazing guy with years of expertise in all things Honda!)

There is one persistent code that pops up, but it isn't throwing a CEL. That code is P0AA6, which is "High Voltage Short Circuit", and is the same code that popped up yesterday. Research seems to indicate a ground strap issue, which I know I have after inspecting. Will be replacing the ground straps ASAP as well as ordering a new 12V battery. I probably won't get sub-zero temperatures here, but I can't guarantee it, so I'll stick with the typical lead acid since the hybrid battery works fine. There are no codes whatsoever for hybrid battery deterioration.

Hopefully this helps fix all the issues!

(smacks myself for being so ready to throw out the IMA)

EDIT: $90 later and I just finished installing the new 12V battery. 500 cold cranking amps; I think the old one was only 400 or 450. Ground straps will arrive Tuesday. Cost $14.60, original Honda parts.
Is it okay to keep driving the Insight until then, or should I park it until I install the new ground straps? Or should I bypass the IMA until then?

[Daox]

I'd drive it. If it was serious it would actually throw the CEL.

Jeez, you're really making me want to work on my Insight...

[mpg_numbers_guy]

Originally Posted by Daox

I'd drive it. If it was serious it would actually throw the CEL.

It did yesterday. It hasn't yet today but I also grid charged it and reset the battery.

Originally Posted by Daox

Jeez, you're really making me want to work on my Insight...

Why aren't you?

[Ecky]

Originally Posted by mpg_numbers_guy

It did yesterday. It hasn't yet today but I also grid charged it and reset the battery.



Why aren't you?

Worked on mine and my partner's Fit all day today!

It's been between 10F and -5F the last few weeks, today we actually had a day in the upper 30's! It was practically balmy outside.

[mpg_numbers_guy]

Drove the Insight home tonight and the IMA/CEL lights came back on after about 5 miles. This time the code is P0A7F - Hybrid Battery Pack Deterioration. Got the same symptoms as before - weaker assist, no regen, no regen or assist displayed on dash, no autostop, but still starting off the hybrid battery. Hoping this isn't what it seems and that the ground straps will fix everything. We'll have to see. Got 73.5 MPG on the way home with little assistance from the pack.

Here's what happened. The hybrid charge level reset because of replacing the 12V battery. The hybrid battery was 3 bars from full at the time. As I left the dealership, it was force regenning since the battery pack was showing empty due to the 12V reset. After a couple miles it quickly climbed to full and worked normally for a few more miles. Then it quickly drained while I wasn't using any assist at all, force regenned for a couple miles, and then threw the code.

Originally Posted by Ecky

Worked on mine and my partner's Fit all day today!

What did you do to it?

Originally Posted by Ecky

It's been between 10F and -5F the last few weeks, today we actually had a day in the upper 30's! It was practically balmy outside.

30s-40s here in Michigan. Roads iced last night but not bad for December actually. Haven't had any issues still running Bridgestones yet. Maybe it's a good thing that the weather is good, not only for fuel economy and being able to work on the car, but also because winter tires in the Insight's size are out of stock everywhere.

[Ecky]

Lower grille block, warm air intake, ran a 120v outlet through the firewall so she can pre-warm her cabin, checked tire pressure, swapped out one more bulb for an LED. She gets pretty phenomenal economy - I think mid 40's when the weather is good. Haven't kept track lately.